Sounds like a very nice sized place! Good possibilities...i am renting a room with dimensions of: W8500 mm x L5800 mm. It has sloped ceiling thus the lower end by the windows is H2830 mm and the high end is H3820 mm (you can see the image below):
... "on the same floor" ??? That implies that you are not on the ground floor? You are on an upper floor?and two other studios on the same floor which have no problem with the sound since they are also well isolated.
I don't understand: you already HAVE the outer leaf! you said it is brick and measures 8.5m x 5.8m x 2.8-3.2m. That IS your outer leaf. You don't need another one!add fireproof gypsum to the outer leaf of the room.
Why are you cutting off the corners like that? Corners are excellent places for bass trapping: by eliminating the corners, you are wasting a lot of space, and throwing away great opportunities for treatment.You can see my CR concept here:
I keep on seeing that shape, but I'm not sure where it comes from: Either it is being totally misused, out of context, or it is just one of those infamous Internet myths that carries on circulating but refuses to die the death it deserves...
Louden's third ratio? Why did you choose that one, when you have so much space available, and opportunities for a better ratio in a larger room?The room ratio i have chosen is as follows: 1:1,5:2,13
Imagine that you are standing inside the room, right after you finish building it, but before you put in any furniture or acoustic treatment. The hard, solid, massive, rigid walls that you see around you, are the ones you use for calculating the room modes.1) Am i calculating the room dimensions correctly? What i mean by this question is: which dimensions of the outer leaf are used to calculate the ratio correctly?
However, with the sixteen-sided room shape that you are showing, you cannot use Bob Golds' calculator, nor any other simple calculator. All room mode calculators assume that your room has only six sides, arranged as a rectangular prism, with three pairs of parallel boundary surfaces, at right angles to each other. Those calculators will not produce valid, realistic predictions for your multi-walled, multi-angled non-parallel room.
It would be, if your room was a 6-sided rectangle. But that's not the case, so your predicted Bonello chart is pretty much meaningless.I have done a room modes analysis and the Bonello diagram comes out as follows (which to my knowledge is pretty fine):
I am thinking that it creates a wonderful resonant cavity, where bass will build up fantastically, without any damping at all, totally messing up the room acoustics, and making the rear 3 meters of the room unusable for critical listening.2) What do you think about the square niche in back side of the CR?
How? You are cutting off the front corners where the soffits need to go.3) The speakers will be soffit mounted,
Assuming that the small angled "cut-off" walls at the front left and right are what you are referring to as "soffits", the answer is no: they are likely too small to be of much use.but I have concerns weather the front soffit panel will be large enough for the speaker?
Soffit mounting is an excellent concept, and very much recommended... but it has to be done right.
I have read a LOT of things about sound on the internet: only a small fraction of them turn out to be true.I have read that the soffit panel should be 0.25 of lowest wavelength the speaker produces.
In reality, the concept of soffit mounting is to create an "infinite baffle", meaning a front surface that appears to be infinitely large to the sound waves emanating from the speaker. That's a lofty goal, as theoretically it would have to measure hundreds of meters in all directions to do that. Happily, it isn't necessary to do that. One full wavelength in all directions will do the job reasonably well: Sadly, that still means that you'd need a soffit a dozen meters each way: hard to do, realistically, in most real-world studios. So we have to compromise, by going smaller. The smaller you go, the less effect you get. A quarterwave is a good compromise, but even that isn't achievable in most studios. So you have to go smaller still. In the real world, as long as you can at least double the width of the speaker cabinet itself, you are doing well. If you can go more than that, then excellent. Vertically, you often can get close to a quarter wave, but horizontally, that's tough, unless you have a very big room.
There are also other issues: with small sizes vs. wavelengths, you start getting "focusing" or "lobing" effects, and to compensate for that, you need to offset the speaker so that it is NOT in the middle of the soffit. On the plus side, you can blend the soffit wall into the front wall and side wall, increasing the effect. On the down-side, that creates a sort of horn-loading shape for the speaker, which might or might not be good. On the up-side....
As you can see, there are lots of "up" sides and lots of "down" sides to designing a soffit. The basic plan is to make it as big as you possibly can (by eliminating the unnecessary angled side-wall cut-off thingies, for example) and to offset the speaker form the center as much as you reasonably can do. The rest can be done at the stage of room tuning, to a certain extent.
Yes and no. "Yes" if you have the space to do so without unduly affecting your room volume, and if you need to do that for treatment reasons. "No" otherwise. "Yes" if the design concept you are following requires that, "No" otherwise.4) I am not sure if i should angle my inner leaf walls or not.
Yep. Count me in. I only ever angle walls these days where it is absolutely needed to create an RFZ, NER, CID or similar room, and even then I only angle as much wall as is totally necessary. The rest I leave parallel then treat accordingly, unless there is a powerful overriding reason to do otherwise.but John has stated in some of them that he is not opting for angled walls anymore, some other guys say that too.
Correct! Modes are a fact of life, and ALL rooms have them regardless of shape or size. You should go with a basic rectangular shape that has a set of overall dimensions that show no major modal issues, then work from there. By angling the front part of the room, you will be "softening" the effects of the axial modes, and also adding tangential modes. That's a good thing. But you are right: as long as you have a fairly decent basic shape, you do not need to go crazy about modal response.I understand modes are much harder to calculate with angled walls, but then again - i dont know much about that and im not sure if i really MUST calculate them very extensively?
Move the entire structure over to the left wall, and up against the back wall, so that you can eliminate those parts of what you are showing. In other words, use two sides of the existing room as two sides of your outer leaf, then just build the other two sides to complete the outer shell.5) Is the approach Ive chosen correct? Maybe I should choose some other design with the room i have? The reason behind this design is because i am still planning to leave a small space in the front for my mersonal office where i would do my engineering work.
- Stuart -